JP4500916B2

JP4500916B2 - Magnesium alloy and manufacturing method thereof

Info

Publication number: JP4500916B2
Application number: JP2004280878A
Authority: JP
Inventors: 裕一家永; 能人河村; 英小園; 毅山口
Original assignee: Honda Motor Co Ltd; Japan Steel Works Ltd; Fuji Light Metal Co Ltd
Current assignee: Honda Motor Co Ltd; Japan Steel Works Ltd; Fuji Light Metal Co Ltd
Priority date: 2004-09-28
Filing date: 2004-09-28
Publication date: 2010-07-14
Anticipated expiration: 2024-09-28
Also published as: US20060065332A1; EP1640466B1; JP2006097037A; DE602005015799D1; EP1640466A1

Description

本発明は、高強度と高延性とを兼ね備えるマグネシウム合金及びその製造方法に関するものである。 The present invention relates to a magnesium alloy having both high strength and high ductility and a method for producing the same.

マグネシウムは、鉄、アルミニウムに比べて軽量であるため、鉄鋼材料、アルミニウム合金材料からなる部材に代わる軽量代替材として用いることが検討されている。ところが、一般のマグネシウム合金は、鉄鋼、アルミニウム合金、チタン合金等の他の金属構造材料に比較して強度が低く、比較的高強度とされるダイキャスト用のＡＺ９１材ですら１６０ＭＰａ程度である。また、産業用部品等の可動部では少なくとも４〜５％の伸びが必要とされるが、一般のマグネシウム合金は延性についても十分とは言えず、前記ＡＺ９１材で３％程度である。 Since magnesium is lighter than iron and aluminum, it has been studied to be used as a lightweight substitute material in place of a member made of a steel material or an aluminum alloy material. However, a general magnesium alloy has a strength lower than that of other metal structural materials such as steel, an aluminum alloy, and a titanium alloy, and even an AZ91 material for die casting that has a relatively high strength is about 160 MPa. In addition, at least 4 to 5% of elongation is required for movable parts such as industrial parts, but a general magnesium alloy cannot be said to have sufficient ductility, and is about 3% for the AZ91 material.

そこで、従来、高強度と高延性とを備えるマグネシウム合金が種々提案されている。 Therefore, various magnesium alloys having high strength and high ductility have been proposed.

例えば、一般式：Ｍｇ_{１００−ａ−ｂ−ｃ}Ｃａ_ａＺｎ_ｂＸ_ｃ、但しＸはＹ、Ｃｅ、Ｌａ、Ｎｄ、Ｐｒ、Ｓｍ、Ｍｍ（ミッシュメタル）からなる群から選ばれる１種または２種以上の元素であり、０．５≦ａ≦５原子％、０＜ｂ≦５原子％、０＜ｃ≦３原子％、但し１≦ａ＋ｂ＋ｃ≦１１原子％である組成を有し、かつ、微細結晶質からなる母相に、Ｍｇ−Ｃａ系、Ｍｇ−Ｚｎ系、Ｍｇ−Ｘ系金属間化合物の１種または２種以上が微細に分散した組織を有するマグネシウム合金が知られている。前記金属間化合物を有するマグネシウム合金は、前記組成を備える溶融合金を、アトマイズ法等により急冷凝固させることにより粉末の高強度マグネシウム合金とすることができ、該粉末を熱間塑性加工することにより、複雑な形状に成形加工することができるとされている（特許文献１参照）。 For example, the general formula: Mg _100-abc Ca _a Zn _b X _c , where X is one or two selected from the group consisting of Y, Ce, La, Nd, Pr, Sm, Mm (Misch metal) An element of at least species, having a composition of 0.5 ≦ a ≦ 5 atomic%, 0 <b ≦ 5 atomic%, 0 <c ≦ 3 atomic%, where 1 ≦ a + b + c ≦ 11 atomic%, and There is known a magnesium alloy having a structure in which one or more of Mg—Ca, Mg—Zn, and Mg—X intermetallic compounds are finely dispersed in a fine crystalline matrix. The magnesium alloy having the intermetallic compound can be made into a high strength magnesium alloy of powder by rapidly solidifying a molten alloy having the composition by an atomizing method or the like, and by hot plastic working the powder, It can be formed into a complicated shape (see Patent Document 1).

また、一般式：Ｍｇ_{１００−ａ−ｂ}Ｌｎ_ａＭ_ｂ、但しＭはＡｌ、Ｚｎから選ばれる１種以上の元素であり、ＬｎはＹ、Ｃｅ、Ｌａ、Ｎｄ、Ｐｒ、Ｐｍ、Ｓｍ、Ｅｕ、Ｇｄ、Ｔｂ、Ｄｙ、Ｈｏ、Ｅｒ、Ｔｍ、Ｙｂ、Ｌｕ、Ｍｍ（ミッシュメタル）からなる群から選ばれる１種以上の元素または希土類元素の混合体であり、０．５≦ａ≦５原子％、０．２≦ｂ≦４原子％、但し１．５≦ａ＋ｂ≦７原子％である組成を有し、かつ、結晶粒径が２０００ｎｍ未満であり、結晶中の一部または全域に長周期六方構造を有するマグネシウム合金が知られている。前記長周期六方構造を有するマグネシウム合金は、前記組成を備える溶融合金を、アトマイズ法等により急冷凝固させることにより粉末の高強度高延性のマグネシウム合金とすることができ、該粉末を押出比３〜２０で塑性加工することにより該マグネシウム合金からなる成形材を得ることができるとされている（特許文献２参照）。 Further, the general formula: Mg _100-ab Ln _a M _b , where M is one or more elements selected from Al and Zn, and Ln is Y, Ce, La, Nd, Pr, Pm, Sm, Eu , Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Mm (Misch metal), a mixture of one or more elements selected from the group consisting of rare earth elements and 0.5 ≦ a ≦ 5 atoms %, 0.2 ≦ b ≦ 4 atomic%, where 1.5 ≦ a + b ≦ 7 atomic%, the crystal grain size is less than 2000 nm, and a long period is partially or entirely in the crystal. Magnesium alloys having a hexagonal structure are known. The magnesium alloy having the long-period hexagonal structure can be made into a high-strength, high-ductility magnesium alloy of powder by rapidly solidifying a molten alloy having the above composition by an atomizing method or the like. It is said that a molded material made of the magnesium alloy can be obtained by plastic working at 20 (see Patent Document 2).

しかしながら、前記マグネシウム合金は、いずれも前記溶融合金を急冷凝固させる際の歩留まりが低く、前記急冷凝固により得られた粉末から成形体を形成しようとするとコストの増大が避けられないという不都合がある。また、前記マグネシウム合金は、いずれも伸びが５％以下で産業用部品の可動部に使用できる限界値に近く、十分な延性を備えているとは言い難いため、設計の自由度が大きく制限されて実用性が低くなるという不都合がある。 However, any of the magnesium alloys has a low yield when the molten alloy is rapidly solidified, and there is an inconvenience that an increase in cost is inevitable when trying to form a compact from the powder obtained by the rapid solidification. In addition, since the magnesium alloys have an elongation of 5% or less and are close to the limit values that can be used for movable parts of industrial parts, it is difficult to say that they have sufficient ductility. There is an inconvenience that the practicality becomes low.

一方、前記長周期六方構造を有するマグネシウム合金は、冷却速度の大きな銅製鋳型を用いて鋳造を行うことにより成形体を得ることもできるとされている。しかしながら、前記銅製鋳型を用いる場合には、冷却速度を大きくするために、比較的小型の成形体しか製造することができず、成形体の大きさが制限されるという不都合がある。
特開平９−４１０６５号公報特開２００２−２５６３７０号公報長野真之、西田稔、河村能人、急速凝固Ｍｇ−Ｚｎ−Ｙ合金の組織形成に及ぼすＺｎ，Ｙ濃度と熱処理の影響、「日本金属学会講演概要」、日本金属学会、２００３年、ｐ．１８７ On the other hand, the magnesium alloy having the long-period hexagonal structure is said to be capable of obtaining a molded body by casting using a copper mold having a high cooling rate. However, when the copper mold is used, in order to increase the cooling rate, only a relatively small molded body can be manufactured, and there is a disadvantage that the size of the molded body is limited.
Japanese Patent Laid-Open No. 9-41065 JP 2002-256370 A Masayuki Nagano, Satoshi Nishida, Nobuto Kawamura, Effects of Zn, Y concentration and heat treatment on the structure formation of rapidly solidified Mg-Zn-Y alloy, "Metal Society of Japan Lecture Summary", Japan Institute of Metals, 2003, p. 187

本発明は、かかる不都合を解消して、安価で歩留まりが良く、成形体の大きさに制限が無く、しかも高強度と高延性とを兼ね備えるマグネシウム合金及びその製造方法を提供することを目的とする。 An object of the present invention is to provide a magnesium alloy that eliminates such inconveniences, is inexpensive, has a good yield, has no limitation on the size of the molded body, and has both high strength and high ductility, and a method for producing the same. .

かかる目的を達成するために、本発明のマグネシウム合金は、全量に対して、Ｚｎ１〜４原子％と、Ｙ１〜４．５原子％とを含み、残部がＭｇと不可避の不純物とからなり、ＺｎとＹとの組成比Ｚｎ／Ｙが０．６〜１．３の範囲にある組成を備え、金属間化合物Ｍｇ_３Ｙ_２Ｚｎ_３と、長周期構造を示すＭｇ_１２ＹＺｎとを含むことを特徴とする。 In order to achieve this object, the magnesium alloy of the present invention contains Zn 1 to 4 atomic% and Y 1 to 4.5 atomic% with respect to the total amount, and the balance is composed of Mg and inevitable impurities. The composition ratio Zn / Y between Y and Y is in the range of 0.6 to 1.3, and includes an intermetallic compound Mg ₃ Y ₂ Zn ₃ and Mg ₁₂ YZn having a long-period structure. And

本発明のマグネシウム合金は、前記組成を備えると共に、前記金属間化合物Ｍｇ_３Ｙ_２Ｚｎ_３と、長周期構造を示すＭｇ_１２ＹＺｎとの両方を含むことにより、高強度と高延性とを兼ね備えることができる。マグネシウム合金の全量に対して、Ｚｎが１原子％未満または４原子％を超え、Ｙが１原子％未満または４．５原子％を超えるときには、強度または延性のいずれか一方、または両方が不十分になる。 The magnesium alloy of the present invention has the above composition and has both high strength and high ductility by including both the intermetallic compound Mg ₃ Y ₂ Zn ₃ and Mg ₁₂ YZn exhibiting a long-period structure. Can do. When Zn is less than 1 atomic% or greater than 4 atomic% and Y is less than 1 atomic% or greater than 4.5 atomic% with respect to the total amount of the magnesium alloy, either strength or ductility, or both are insufficient. become.

また、マグネシウム合金の全量に対して、ＺｎとＹとが共に前記範囲の組成を備えていても、該マグネシウム合金に前記金属間化合物Ｍｇ_３Ｙ_２Ｚｎ_３と、長周期構造を示すＭｇ_１２ＹＺｎとのいずれか一方、または両方が含まれていないときには、強度または延性のいずれか一方、または両方が不十分になる。 Moreover, even if both Zn and Y have the composition in the above range with respect to the total amount of the magnesium alloy, the magnesium alloy includes the intermetallic compound Mg ₃ Y ₂ Zn ₃ and Mg ₁₂ YZn exhibiting a long-period structure. When either or both are not included, either strength or ductility, or both are insufficient.

さらに、本発明のマグネシウム合金は、前記金属間化合物Ｍｇ_３Ｙ_２Ｚｎ_３と、長周期構造を示すＭｇ_１２ＹＺｎとの両方を確実に含むために、前記ＺｎとＹとの組成比Ｚｎ／Ｙが０．６〜１．３の範囲にあることが必要である。前記ＺｎとＹとの組成比Ｚｎ／Ｙが０．６未満または１．３を超えるときには、前記マグネシウム合金に前記金属間化合物Ｍｇ_３Ｙ_２Ｚｎ_３と、長周期構造を示すＭｇ_１２ＹＺｎとのいずれか一方、または両方が含まれないことがある。 Furthermore, since the magnesium alloy of the present invention surely contains both the intermetallic compound Mg ₃ Y ₂ Zn ₃ and Mg ₁₂ YZn having a long-period structure, the composition ratio Zn / Y of the Zn and Y Must be in the range of 0.6 to 1.3. When the composition ratio Zn / Y between Zn and Y is less than 0.6 or exceeds 1.3, the magnesium alloy includes the intermetallic compound Mg ₃ Y ₂ Zn ₃ and Mg ₁₂ YZn having a long-period structure. Either one or both may not be included.

尚、急速凝固Ｍｇ−Ｚｎ−Ｙ合金において、ＭｇＺｎＹ_Ｘ（Ｘ＝２〜４）のＹ濃度＞Ｚｎ濃度の合金ではＹ濃度が大になるほど長周期構造が増加し、ＭｇＺｎ_ＸＹ（Ｘ＝２〜４）のＺｎ濃度＞Ｙ濃度の合金では熱処理により前記金属間化合物Ｍｇ_３Ｙ_２Ｚｎ_３が析出し、ＭｇＺｎ_ＸＹ_Ｘ（Ｘ＝１〜４）でありＹ濃度＝Ｚｎ濃度の等原子比合金では熱処理により前記長周期構造が生成することは知られている（非特許文献１参照）。 Note that in rapidly solidified MgZn-Y _alloy, increases as the long-period structure Y concentration of large the alloy of Y concentration> Zn concentration MgZnY X (X = 2~4), MgZn X Y (X = 2 To 4), the intermetallic compound Mg ₃ Y ₂ Zn ₃ is precipitated by heat treatment, and MgZn _X Y _X (X = 1 to 4), where Y concentration = Zn concentration is equiatomic ratio. It is known that the long-period structure is generated by heat treatment in an alloy (see Non-Patent Document 1).

しかし、本発明者らの検討によれば、前記Ｙ濃度＞Ｚｎ濃度の合金と、前記Ｙ濃度＝Ｚｎ濃度の等原子比合金とでは、前記金属間化合物Ｍｇ_３Ｙ_２Ｚｎ_３が存在せず、前記Ｚｎ濃度＞Ｙ濃度の合金では前記長周期構造が存在しない。従って、前記急速凝固Ｍｇ−Ｚｎ−Ｙ合金では、前記長周期構造と前記金属間化合物Ｍｇ_３Ｙ_２Ｚｎ_３とが共存することはない。 However, according to the study by the present inventors, the intermetallic compound Mg ₃ Y ₂ Zn ₃ does not exist in the alloy having the Y concentration> Zn concentration and the equiatomic ratio alloy having the Y concentration = Zn concentration. In the alloy of Zn concentration> Y concentration, the long-period structure does not exist. Therefore, in the rapidly solidified Mg—Zn—Y alloy, the long-period structure and the intermetallic compound Mg ₃ Y ₂ Zn ₃ do not coexist.

本発明のマグネシウム合金は、優れた高強度と高延性とを兼ね備えるために、全量に対して、Ｚｎ２〜３．５原子％と、Ｙ２〜４．５原子％とを含み、残部がＭｇと不可避の不純物とからなり、ＺｎとＹとの組成比Ｚｎ／Ｙが０．８〜１．２の範囲にある組成を備えることが好ましい。 Since the magnesium alloy of the present invention has both excellent high strength and high ductility, it contains Zn 2 to 3.5 atomic% and Y 2 to 4.5 atomic% with respect to the total amount, and the balance is inevitable with Mg. consists of a impurity, it is preferable to provide a composition composition ratio Zn / Y between Zn and Y is in the range of 0.8 to 1.2.

また、本発明のマグネシウム合金は、全量に対して、Ｚｎ１〜４原子％と、Ｙ１〜４．５原子％とを含み、残部がＭｇと不可避の不純物とからなるものであってもよいが、さらに全量に対して、Ｚｒ０．１〜０．５原子％とを含み、残部がＭｇと不可避の不純物とからなるものであってもよい。 Further, the magnesium alloy of the present invention may contain Zn 1 to 4 atomic% and Y 1 to 4.5 atomic% with respect to the total amount, and the balance may be composed of Mg and inevitable impurities. Furthermore, it may contain Zr0.1-0.5 atomic% with respect to the whole quantity, and the remainder may consist of Mg and inevitable impurities.

本発明のマグネシウム合金は、Ｚｒを前記範囲で含むことにより、合金組織を微細化すると共に、前記金属間化合物Ｍｇ_３Ｙ_２Ｚｎ_３の生成を促進することができる。Ｚｒの含有量が合金全量に対して０．１原子％未満では合金組織を微細化し、前記金属間化合物Ｍｇ_３Ｙ_２Ｚｎ_３の生成を促進する効果を得ることができず、０．５原子％を超えると前記金属間化合物Ｍｇ_３Ｙ_２Ｚｎ_３の生成を阻害することがある。 By including Zr in the above range, the magnesium alloy of the present invention can refine the alloy structure and promote the formation of the intermetallic compound Mg ₃ Y ₂ Zn ₃ . If the Zr content is less than 0.1 atomic% with respect to the total amount of the alloy, the alloy structure is refined, and the effect of promoting the formation of the intermetallic compound Mg ₃ Y ₂ Zn ₃ cannot be obtained. When it exceeds%, production of the intermetallic compound Mg ₃ Y ₂ Zn ₃ may be inhibited.

また、本発明のマグネシウム合金は、前記組成にＬａ、Ｃｅ、Ｎｄ、Ｓｍ、Ｙｂからなる群から選択される少なくとも１種の元素を少量添加することによりさらに高強度化することもできる。また、本発明のマグネシウム合金は、繊維、粒子等の強化材を添加することにより、コンポジット化することもできる。 The magnesium alloy of the present invention can be further strengthened by adding a small amount of at least one element selected from the group consisting of La, Ce, Nd, Sm, and Yb to the composition. The magnesium alloy of the present invention can also be made into a composite by adding reinforcing materials such as fibers and particles.

本発明のマグネシウム合金は、全量に対して、Ｚｎ１〜４原子％と、Ｙ１〜４．５原子％とを含み、残部がＭｇと不可避の不純物とからなり、ＺｎとＹとの組成比Ｚｎ／Ｙが０．６〜１．３の範囲にある組成を備えるＭｇ合金を鋳造後、塑性加工することにより、金属間化合物Ｍｇ_３Ｙ_２Ｚｎ_３と、長周期構造を示すＭｇ_１２Ｚｎとを含む合金組織とする方法により製造することができる。 The magnesium alloy of the present invention contains Zn 1 to 4 atomic% and Y 1 to 4.5 atomic% with respect to the total amount, the balance being composed of Mg and inevitable impurities, and the composition ratio Zn / Y of Zn / Y After casting an Mg alloy having a composition with Y in the range of 0.6 to 1.3, plastic processing is performed, thereby including an intermetallic compound Mg ₃ Y ₂ Zn ₃ and Mg ₁₂ Zn exhibiting a long-period structure. It can be manufactured by a method of forming an alloy structure.

次に、本発明の実施の形態についてさらに詳しく説明する。 Next, embodiments of the present invention will be described in more detail.

本実施形態では、まず、合金全量に対して、Ｚｎ１〜４原子％と、Ｙ１〜４．５原子％とを含み、ＺｎとＹとの組成比Ｚｎ／Ｙが０．６〜１．３の範囲にあり、さらに好ましくはＺｒ０．１〜０．５原子％とを含み、残部がＭｇと不可避の不純物とからなる材料をカーボン坩堝に収容し、アルゴン雰囲気下、高周波溶解炉中で例えば７００℃の温度で溶解し、溶融合金を得る。 In this embodiment, first, Zn 1 to 4 atomic% and Y 1 to 4.5 atomic% are included with respect to the total amount of the alloy, and the composition ratio Zn / Y between Zn and Y is 0.6 to 1.3. In a range, and more preferably containing Zr 0.1 to 0.5 atomic%, the balance of Mg and inevitable impurities is housed in a carbon crucible, for example 700 ° C. in a high-frequency melting furnace in an argon atmosphere To obtain a molten alloy.

次に、前記溶融合金を鋳型に注入して鋳造を行う。前記鋳造における冷却速度は、１０Ｋ／秒以下とすることが好ましい。前記冷却速度は、急冷凝固の際のアトマイズ法または双ロール法の１０^４Ｋ／秒以上、あるいはロールキャスト法または急冷銅製鋳型法の１０^３〜１０^２Ｋ／秒に比較して格段に低い。従って、本実施形態において、前記鋳型は、金型、黒鉛型、砂型等の一般的なものを用いることができ、銅製鋳型または水冷銅製鋳型等を用いる必要がなく、コストを低減することができる。 Next, the molten alloy is poured into a mold and cast. The cooling rate in the casting is preferably 10 K / second or less. The cooling rate is much lower than 10 ⁴ K / second in the atomization method or twin roll method during rapid solidification, or 10 ³ to 10 ² K / second in the roll cast method or quenched copper mold method. Therefore, in the present embodiment, the mold can be a general mold such as a mold, a graphite mold, a sand mold, etc., and it is not necessary to use a copper mold or a water-cooled copper mold, and the cost can be reduced. .

次に、得られた鋳造物を塑性加工することにより成形物を得る。前記成形物は、合金全量に対して、Ｚｎ１〜４原子％と、Ｙ１〜４．５原子％とを含み、ＺｎとＹとの組成比Ｚｎ／Ｙが０．６〜１．３の範囲にあり、さらに好ましくはＺｒ０．１〜０．５原子％とを含み、残部がＭｇと不可避の不純物とからなるマグネシウム合金であり、金属間化合物Ｍｇ_３Ｙ_２Ｚｎ_３と、長周期構造を示すＭｇ_１２ＹＺｎとの両方を含んでいる。この結果、前記成形物は、高強度と高延性とを兼ね備えることができる。 Next, a molded product is obtained by plastic processing the obtained casting. The molded product contains Zn 1 to 4 atomic% and Y 1 to 4.5 atomic% with respect to the total amount of the alloy, and the composition ratio Zn / Y of Zn and Y is in the range of 0.6 to 1.3. And more preferably a magnesium alloy containing 0.1 to 0.5 atomic% of Zr, with the balance being composed of Mg and inevitable impurities, and intermetallic compound Mg ₃ Y ₂ Zn ₃ and Mg exhibiting a long-period structure. ₁₂ YZn and both. As a result, the molded product can have both high strength and high ductility.

次に本発明の実施例と比較例、参考例とを示す。 Next, examples of the present invention, comparative examples, and reference examples are shown.

本実施例では、合金全量に対して、Ｚｎ１〜４原子％と、Ｙ１〜４．５原子％とを含み、ＺｎとＹとの組成比Ｚｎ／Ｙが０．６〜１．３の範囲にあり、さらに好ましくはＺｒ０．１〜０．５原子％とを含み、残部がＭｇと不可避の不純物とからなり、Ｚｎ、Ｙ、Ｚｒをそれぞれ前記範囲内で変量した材料をカーボン坩堝に収容し、アルゴン雰囲気下、高周波溶解炉中で例えば７００℃の温度で溶解した。次に、得られた溶融合金を金型に注入し、１０Ｋ／秒以下の冷却速度で鋳造を行い、丸棒材を得た。次に、前記丸棒材を電気炉で３５０〜４５０℃の範囲の温度に加熱し、押出比１０で押出成形を行って、成形物を得た。 In the present embodiment, Zn is contained in 1 to 4 atomic% and Y1 to 4.5 atomic% with respect to the total amount of the alloy, and the composition ratio Zn / Y between Zn and Y is in the range of 0.6 to 1.3. And, more preferably, containing Zr 0.1 to 0.5 atomic%, the balance is made of Mg and inevitable impurities, and the materials in which Zn, Y and Zr are varied within the above ranges are accommodated in a carbon crucible, It melt | dissolved at the temperature of 700 degreeC, for example in the high frequency melting furnace in argon atmosphere. Next, the obtained molten alloy was poured into a mold and cast at a cooling rate of 10 K / second or less to obtain a round bar. Next, the round bar was heated in an electric furnace to a temperature in the range of 350 to 450 ° C., and extrusion molding was performed at an extrusion ratio of 10 to obtain a molded product.

得られた成形物の金属組織をＸ線回折及び透過型電子顕微鏡により同定し、金属間化合物Ｍｇ_３Ｙ_２Ｚｎ_３と、長周期構造を示すＭｇ_１２ＹＺｎとの有無を確認した。また、前記成形物から試験片を切り出し、常温で引張試験を行って、０．２％耐力、引張強さ、伸びを測定した。結果を表１に示す。
〔比較例〕
本比較例では、合金全量に対して、Ｚｎ０．５〜５原子％と、Ｙ０．５〜５原子％とを含み、残部がＭｇと不可避の不純物とからなり、Ｚｎ、Ｙをそれぞれ前記範囲内で変量した材料を用いた以外は、前記実施例と全く同一にして丸棒材を得て、該丸棒材に対して前記実施例と全く同一にして押し出し成形を行い、成形物を得た。 The metal structure of the obtained molding was identified by X-ray diffraction and a transmission electron microscope, and the presence or absence of the intermetallic compound Mg ₃ Y ₂ Zn ₃ and Mg ₁₂ YZn having a long-period structure was confirmed. In addition, a test piece was cut out from the molded product and subjected to a tensile test at room temperature to measure 0.2% proof stress, tensile strength, and elongation. The results are shown in Table 1.
[Comparative Example]
In this comparative example, with respect to the total amount of the alloy, 0.5 to 5 atomic% of Zn and 0.5 to 5 atomic% of Y are included, the balance is composed of Mg and inevitable impurities, and Zn and Y are within the above ranges, respectively. A round bar was obtained in exactly the same manner as in the above example except that the material changed in the above was used. Extrusion molding was performed on the round bar in exactly the same manner as in the above example to obtain a molded product. .

得られた成形物の金属組織をＸ線回折及び透過型電子顕微鏡により同定し、金属間化合物Ｍｇ_３Ｙ_２Ｚｎ_３と、長周期構造を示すＭｇ_１２ＹＺｎとの有無を確認した。また、前記成形物から試験片を切り出し、常温で引張試験を行って、０．２％耐力、引張強さ、伸びを測定した。結果を表１に示す。
〔参考例〕
本比較例では、公知のマグネシウム合金、ＷＥ５４−Ｔ６材、ＡＺ９１材の金属組織をＸ線回折及び透過型電子顕微鏡により同定し、金属間化合物Ｍｇ_３Ｙ_２Ｚｎ_３と、長周期構造を示すＭｇ_１２ＹＺｎとの有無を確認した。また、前記ＷＥ５４−Ｔ６材、ＡＺ９１材から試験片を切り出し、常温で引張試験を行って、０．２％耐力、引張強さ、伸びを測定した。結果を表１に示す。 The metal structure of the obtained molding was identified by X-ray diffraction and a transmission electron microscope, and the presence or absence of the intermetallic compound Mg ₃ Y ₂ Zn ₃ and Mg ₁₂ YZn having a long-period structure was confirmed. In addition, a test piece was cut out from the molded product and subjected to a tensile test at room temperature to measure 0.2% proof stress, tensile strength, and elongation. The results are shown in Table 1.
[Reference example]
In this comparative example, the metal structures of a known magnesium alloy, WE54-T6 material, and AZ91 material are identified by X-ray diffraction and a transmission electron microscope, and the intermetallic compound Mg ₃ Y ₂ Zn ₃ and Mg exhibiting a long-period structure are identified. The presence or absence of ₁₂ YZn was confirmed. Moreover, the test piece was cut out from the said WE54-T6 material and AZ91 material, the tensile test was done at normal temperature, and 0.2% yield strength, tensile strength, and elongation were measured. The results are shown in Table 1.

表１から、合金全量に対し、Ｚｎ１〜４原子％と、Ｙ１〜４．５原子％とを含み、ＺｎとＹとの組成比Ｚｎ／Ｙが０．６〜１．３の範囲にあり、金属間化合物Ｍｇ_３Ｙ_２Ｚｎ_３と、長周期構造を示すＭｇ_１２ＹＺｎとの両方を含む実施例１〜１４のマグネシウム合金によれば、強度（０．２％耐力、引張強さ）、延性（伸び）のいずれも、公知のＷＥ５４−Ｔ６材、ＡＺ９１材に比較して格段に優れており、高強度と高延性とを兼ね備えていることが明らかである。 From Table 1, with respect to the total amount of the alloy, it contains Zn 1 to 4 atomic% and Y 1 to 4.5 atomic%, and the composition ratio Zn / Y of Zn and Y is in the range of 0.6 to 1.3, According to the magnesium alloys of Examples 1 to 14 including both the intermetallic compound Mg ₃ Y ₂ Zn ₃ and Mg ₁₂ YZn having a long-period structure, strength (0.2% proof stress, tensile strength), ductility Any of (elongation) is remarkably superior to the known WE54-T6 material and AZ91 material, and it is clear that it has both high strength and high ductility.

前記実施例に比較して、ＺｎとＹとの組成比Ｚｎ／Ｙが０．６〜１．３の範囲外である比較例１〜５のマグネシウム合金は、金属間化合物Ｍｇ_３Ｙ_２Ｚｎ_３と、長周期構造を示すＭｇ_１２ＹＺｎとのいずれかを備えず、強度と延性とのいずれかまたは両方が十分に得られないことが明らかである。また、Ｙが１〜４．５原子％の範囲より大きい比較例６のマグネシウム合金は、金属間化合物Ｍｇ_３Ｙ_２Ｚｎ_３を備えず、延性が十分に得られないことが明らかである。また、Ｚｎが１〜４原子％の範囲より小さく、Ｙも１〜４．５原子％の範囲よりも小さい比較例７のマグネシウム合金は、金属間化合物Ｍｇ_３Ｙ_２Ｚｎ_３を備えず、強度が十分に得られないことが明らかである。さらに、Ｚｎが１〜４原子％の範囲より大きく、Ｙも１〜４．５原子％の範囲よりも大きい比較例８のマグネシウム合金は、金属間化合物Ｍｇ_３Ｙ_２Ｚｎ_３と、長周期構造を示すＭｇ_１２ＹＺｎとの両方を含むものの、延性が十分に得られないことが明らかである。 Compared to the embodiment, the magnesium alloy of Comparative Examples 1-5 the composition ratio Zn / Y between Zn and Y is outside the range of 0.6 to 1.3, the intermetallic compound _Mg 3 _Y 2 Zn ₃ And Mg ₁₂ YZn having a long-period structure are not provided, and it is clear that either or both of strength and ductility cannot be obtained sufficiently. Moreover, it is clear that the magnesium alloy of Comparative Example 6 in which Y is greater than the range of 1 to 4.5 atomic% does not include the intermetallic compound Mg ₃ Y ₂ Zn ₃ and does not provide sufficient ductility. Further, the magnesium alloy of Comparative Example 7 in which Zn is smaller than the range of 1 to 4 atomic% and Y is also smaller than the range of 1 to 4.5 atomic% does not include the intermetallic compound Mg ₃ Y ₂ Zn ₃ , and the strength. It is clear that cannot be obtained sufficiently. Furthermore, the magnesium alloy of Comparative Example 8 in which Zn is larger than the range of 1 to 4 atomic% and Y is also larger than the range of 1 to 4.5 atomic% includes the intermetallic compound Mg ₃ Y ₂ Zn ₃ and a long-period structure. It is clear that the ductility cannot be obtained sufficiently although it contains both Mg ₁₂ YZn.

Claims

It contains Zn 1 to 4 atomic% and Y 1 to 4.5 atomic% with respect to the total amount, the balance is made of Mg and inevitable impurities, and the composition ratio Zn / Y between Zn and Y is 0.6 to 1. A magnesium alloy having a composition in the range of .3 and containing an intermetallic compound Mg ₃ Y ₂ Zn ₃ and Mg ₁₂ YZn having a long-period structure.

It contains Zn 2 to 3.5 atomic% and Y 2 to 4.5 atomic% with respect to the total amount, the balance is made of Mg and inevitable impurities, and the composition ratio Zn / Y between Zn and Y is 0.8. The magnesium alloy according to claim 1, comprising a composition in the range of -1.2.

Based on the total amount, and Zn1~4 atomic%, and Y1~4.5 atomic%, and a Zr0.1~0.5 atomic%, Ri Do and a balance of Mg and inevitable impurities, Zn and Y comprising a composition composition ratio Zn / Y in is in the range of 0.6 to 1.3, the intermetallic compound _Mg ₃ _Y 2 Zn 3, you; and a _Mg 12 YZn having a long period structure magnesium alloy.

It contains Zn 1 to 4 atomic% and Y 1 to 4.5 atomic% with respect to the total amount, the balance is made of Mg and inevitable impurities, and the composition ratio Zn / Y between Zn and Y is 0.6 to 1. .3, an alloy structure containing an intermetallic compound Mg ₃ Y ₂ Zn ₃ and Mg ₁₂ YZn having a long-period structure is obtained by plastic processing after casting an Mg alloy having a composition in the range of .3. A method for producing a magnesium alloy.